Ranked in these QuestionsQuestion Ranking
Pro Standard on all operating systems
You can find this layout on all operating systems.
Pro You can reuse qwerty layout
Since letters and symbols only change place, but not key, you can change the keys on your keyboard and get a full comfortable Dvorak layout, without having to buy a new keyboard.
Con Not easy on the right pinky finger
Most useful symbols for programming are on the right pinky finger, which is not very comfortable.
Con Inconvenient for common key-shortcuts
Common key bindings such as Ctrl+Z/C/V (and many others) aren't so convenient to access.